Load break interrupter



May 20, 1958 w. E. MITTELSTADT LOAD BREAK I-NTERRUPTER Filed March J2, 1956 IN V EN TOR. WALTER E. MITTELSTADT ATTO RNEY ilnited rates Patent @fiice 2,835,768 Patented May 20, 1958 LOAD BREAK INTERRUPTER Walter E. Mittelstadt, Racine, Wis., assignor to McGraw- Edison Company, a corporation of Delaware Application March 12, 1956, Serial No. 571,097

4 Claims. (Cl. 200-146) This invention relates to improvements in a load break interrupter.

The improvement herein disclosed is particularly di rected to circuit interrupting devices of the nature disclosed in the copending applications of Gerald L. Atkinson, Serial No. 427,557, filed May 4, 1954, now Patent Number 2,785,254, issued March 12, 1957, and Serial No. 567,263, filed February 23, 1956, both of which are assigned to the assignee of the present application.

7 in a load break device wherein, upon disconnecting an electric circuit breaker, the load of the electric line is transferred to an arc interrupter controlled by operation of the breaker, it is necessary to recondition the interrupter after a series of load break operations. Heretofore, the arc interrupter could be reconditioned only after the breaker and interrupter were in open circuit positions. Consequently, the electric circuit would be deenergized during the period of interrupter repair.

It is an object of my invention to provide an are inter rupter which may be manually removed from and replaced in the circuit without operating the breaker to open circuit position, thus maintaining continuity in the transmission of electric power while the interrupter is being repaired.

Other objects and advantages of the invention will become obvious in the following description of the drawings, in which:

Fig. 1 is a top plan view, partly in section.

Fig. 2 is a side view taken from the right relative to Fig. 1.

It will be understood that the terminal plates 1 and 2, with their respective jaw contacts 3 and 4, are each mounted on a fixed insulator (not shown) and that each plate is connected in a suitable well known manner to an electric line (not shown).

The breaker comprises a pair of spaced parallel blades 5 pivotally mounted at one end on a pin 6 spanning the jaw contact 4 and held in frictional contact therewith by a coil spring 7 embracing the pin 6. The opposite ends of the blades 5 are connected to an operating eye 8 and when in closed position, as shown, frictionally engage the jaw contact 3, thus establishing a closed circuit in the electric line.

The load break interrupter, designated in its entirety by the numeral 9, is pivotally mounted between the blades 5. The inner details of the interrupter are not here disclosed since it will be understood that such details are clearly illustrated and described in the aforesaid copending applications.

The interrupter includes an insulating tube 10 closed at one end by a cap 11 having a conductive terminal 12 slidable therein endwise of the tube 10 as more clearly set forth in said copending applications. The other end of the tube 10 is closed by a metallic vented tube 13 having a removable cap 14. The tube 13 is provided with threads 15 which secure it in socketed relation to the mounting sleeve 16. The sleeve 16 is provided with radially opposed trunnions 17 rotatably mounted in the blades 5. A coil spring 18 encircled each trunnion biases the interrupter 9 into substantial parallelism to the blades 5 as indicated by the broken lines in Fig. 2. A pair of cross-bars 19 and 20, one located on one side of the interrupter at one end thereof and the other on the opposite side of the interrupter at the other end thereof, prevent swinging motion of the interrupter in counter-clockwise direction relative to Fig. 2 but allow motion in a clockwise direction under circumstances hereinafter'noted.

The sleeve 16 is provided with a lug 21 projecting radially thereof. Engageable with the lug is a lever arm 22 having a pivot shaft 23 pivotally mounted in one of the blades 5 and projecting to the opposite side thereof. An operating lever 24 with a pull ring 25 is secured to the projecting end of the shaft 23.

When the interrupter 9 is in its normal position substan tially parallel with the blades 5 and the blades are in circuit closing position, the conductive terminal 12on' the interrupter is frictionally engaged between the conductive prongs 26 of the contact 27 which is secured to the terminal plate 1 in any suitable manner, as by a screw bolt 28. Pivotally carried at 29 by the terminal plate 1 is a hook latch 30 normally biased to engage the flanged portion 31 on the terminal 12.

When the breaker is moved to disconnect the blades 5 from the jaw contact 3, the latch 30 holds the interrupter 9 with the contact 12 in engagement with the prongs 26, thereby causing the interrupter to rotate on the trunnions 17 and pulling the contact 12 outwardly endwise of the tube 10. After a predetermined movement of the blades 5 to open position, the contact 12 will be released and retracted into the tube 10 and the interrupter 9 will be returned by the springs 18 to its normal position between the blades. Thus arcing between the blades 5 and jaw contact 3 is avoided while the breaker is moved to open position.

When the breaker and interrupter are in closed position and it is advisable to recondition the interrupter, the interrupter may be removed in the following manner.

To remove the interrupter 9 without opening the circuit, the lineman will insert the hook end of the insulating operating pole in the pull ring 25 of the lever 24 and pull downwardly in the direction of the arrow 32 and by reason of engagement of the lever arm 22 with the lug 21 on the sleeve 16 causing the interrupter to rotate on its pivot 17 in the direction of arrows Six-34. The interrupter is shown in one position of its rotation about its pivot by means of the dot-dash lines. However, in that position, it has not yet cleared the conductive prongs and will, therefore, be moved to a position where the terminal 12 will be relatively remote from the prongs.

It is, of course, contemplated that a spring washer 35 disposed between the lever 24 and the adjacent blade 5 will produce sufiicient friction to counteract the bias of springs 18 and hold the sleeve 16 with the interrupter 9 in desired open position for servicing. Following this operation, the interrupter is then removed from the sleeve 16 by rotating it on the threads 15 whereupon it may be repaired or a new interrupter may be substituted. When the interrupter has been replaced in the sleeve 16 it will, under the influence of the springs 18, be returned to its normal position between the blades 5 upon rotation of the lever 24 in a counter-clockwise direction.

Although I have illustrated a single embodiment of my invention, it will be obvious to those skilled in the art that various modifications may be devised without departing from the spirit of my invention.

From the foregoing, it will be apparent that I have provided a novel arrangement of a circuit breaker and are interrupter in which repair or substitution of the interrupter may be accomplished by removal without ina terfering with the transmission of power during the interval required for replacement or repair.

It will be understood that the invention disclosed herein may be adopted in various modifications by those skilled in the art and, therefore, that the appended claims are not limited to the specific disclosure except where the terms thereof are clearly within the disclosed embodiment.

I claim:

1. In a circuit breaker comprising a pair of spaced substantially parallel blades and an arc interrupter normally disposed between said blades and pivotally supported thereby, the combination with means opposing pivotal movement of said interrupter in one direction from its normal position and biasing means urging said interrupter in said one direction, of an operating lever pivotally carried by one of said blades, and interacting means between said lever and interrupter whereby said interrupter may be moved pivotally against the bias of said biasing means to a position angularly relative to said normal position of said interrupter.

2. In a circuit breaker comprising a pair of spaced substantially parallel blades and an elongated arc interrupter normally disposed between and in substantially parallel relation to said blades, said interrupter being pivotally mounted on said blades intermediate the ends of said interrupter and said blades, the combination with means opposing pivotal movement of said interrupter in one direction from its normal position and biasing means urging said interrupter in said one direction, of an operating lever pivotally mounted on one of said blades at a point offset from the pivotal connection between said interrupter and blades, a lever arm secured to said operating lever and movable therewith, said arm disposed between said interrupter and said one blade, and means on said interrupter extending into the path of movement of said arm, whereby pivotal movement of said operating lever etfects a corresponding movement of said interrupter.

3. In a circuit breaker including a blade, the combination with an arc interrupter pivotally mounted on said blade and having a normal position relative thereto, said interrupter being movable in one direction about its pivot from said normal position independently of movement of said blade, of an actuator lever pivotally mounted on said blade, and means interengaging said lever and interrupter whereby pivotal movement of said lever on said blade effects a corresponding movement of said interrupter independently of movement of said blade.

4. In a circuit breaker including an elongated current carrying element, the combination with an arc interrupter pivotally mounted on said element intermediate the ends thereof, of manually operable means movably mounted on said element operatively engaging said interrupter to efiect pivotal movement thereof independently of movement of said element.

References Cited in the file of this patent UNITED STATES PATENTS 1,393,344 Conrad Oct. 11, 1921 2,344,113 Schultz Mar. 14, 1944 2,469,203 Palme et a1. May 3, 1949 2,621,271 Lindell Dec. 9, 1952 2,710,322 Price June 7, 1955 

